ATP Executive Chairman and President Brad Drewett passed away at his home in Sydney, Australia earlier today, the ATP announced. He was 54.

Drewett, who headed the ATP since January 2012, had been suffering from motor neurone disease (Lou Gehrig’s disease). Drewett has been credited with helping to lead the ATP’s battle to gain a substantial prize-money increase from the Grand Slams, which the tour successfully managed to do this year.

ATP board member Justin Gimelstob tweeted: “Brad, you will always be missed but never forgotten. We all owe you a debt of gratitude and never ending appreciation. Love You, RIP.”

Drewett was a former Top 40 singles and Top 20 doubles player. He was a life-long devotee to the ATP tour, serving as an ATP Player Council representative and from 1993 until 1999, as the Tournament Director of the ATP World Tour's season-ending event since 2001, as well as holding a variety of other ATP positions, including Managing Director of the Asia-Pacific Region from 2003 to 2005, and Chief Executive Officer for the International Group.

“It's very sad for the world of sports and tennis in particular,” Rafael Nadal wrote on his Facebook page. Juan Martin del Potro also called it a “sad day for the sport,” as did Mardy Fish.

ITF President Francesco Ricci Bitti called Drewett a “valued friend and colleague to many of us. His knowledge, experience and enthusiasm will be a great loss to the whole sport.”

Long time ATP Communications official Graeme Agars, who was a friend of Drewett’s, said his fellow Aussie's warmth, integrity and commitment to his work set him apart.

"As somebody who knew Brad firstly through my role as a tennis reporter and then as a colleague, a workmate, a proud fellow Aussie, but mostly as a friend, I am deeply saddened by his passing. Brad was the rarest of all individuals," Agars said. "He earned the respect and admiration of his peers as a player and then kept it as he climbed to the top of the ladder in the administration of the game he so dearly loved. His always friendly and warm personality belied his competitive but very fair nature. Brad's willingness to work tirelessly towards his goals was both admirable and inspiring. He will be deeply missed in the worldwide tennis community. The game has lost a wonderful friend and advocate. "